[LinuxPPS] Patches for kernel 2.6.26-rc8

[Bernhard Schiffner]

On Sunday 06 July 2008 10:31:38 Hal V. Engel wrote:
...
> Second ntp appears to be running in microsecond mode rather than nanosecond
> mode even though I built it against the new kernel header files.  When I
> run ntptime I get:
>
>
> ntp_gettime() returns code 0 (OK)
>   time cc1a25a4.f3dc6000  Sat, Jul  5 2008  9:53:56.952, (.952581),
>   maximum error 2561 us, estimated error 12 us
> ntp_adjtime() returns code 0 (OK)
>   modes 0x0 (),
>   offset 72.000 us, frequency -24.429 ppm, interval 1 s,
>   maximum error 2561 us, estimated error 12 us,
>   status 0x1 (PLL),
>   time constant 4, precision 1.000 us, tolerance 500 ppm,
>
>
> As you can see the precision is 1.000 us.  I built ntp after setting up the
> symllinks in /usr/include that are used to build the LinuxPPS userland
> tools. I had expected that the ntp build would find STA_NANO defined in
> /usr/include/timex.h and that it would do the correct thing.  I also tried
> adding STA_NANO and the other related defines to kernel/sys/timex.h in the
> ntp source tree but I still end up with a non-nano ntp.   It appears there
> something else that I need to do to get ntp into nanosecond mode but I have
> no idea what that would be.  Do I need to do something to the kernel (I
> couldn't find any place to make any config settings that looked like it
> would affect this)?  Do I need to build a newer version of ntp (I have
> tried 4.2.4_p4 and 4.2.5p118)?  Or do I need to use a commad line switch
> when starting ntpd or something in the configuration file?
>
Ther are (small but important) differerences between /usr/include/linux
and /usr/src/kernel/include/linux.
One is what the distributor cleaned up for your use, working with a lot of 
different kernels too. The other is the recent opinion of the 
kernel-community.
Test this please to get it right.
A symlink may help for a first shot, but don't trash the content 
of /usr/include/linux to fast.

..
> Hal

Good luck!

Bernhard